On one level, the Atomic Testing Museum here in Las Vegas echoes a past that now seems strangely distant: the duck-and-cover era of the US-Soviet arms race. Yet its centerpiece exhibit Ground Zero Theater - complete with a flash of light, trembling benches, and a rush of air sweeping through the room - is also a visceral reminder of very present realities and risks.

The cold war, perhaps, is only technically over in an era of tensions over Iran, North Korea, and nuclear trafficking. And in this state, its past of unsung effort and controversial sacrifices lingers long after the mushroom clouds have gone.

"It's only now, after the cold war is over, that we realize that even though it was a 'cold' war, it did [occur] in places," says museum director Bill Johnson. "This museum's position is that the Nevada Test Site was a battleground of the cold war and it helped to end it, and that's a significant position to take."

Nevada's radioactive heritage

Many states played a role in America's nuclear-weapons program, but the museum's location in Nevada is fitting. Nevadans have long had a conflicted relationship with radioactivity, from the state's pride as the home of the 1,375 square-mile nuclear test site to its more recent battles of trying to keep Yucca Mountain exempt from becoming the nation's dumping ground for nuclear reactor waste.

"Our museum is here to show what we did in defense of our country," says Mr. Williams, the docent. "Most people only see the detrimental part of what went on there, but we did many, many things to benefit mankind."

But in paying tribute to the US weapons effort and those who labored on it, the museum comes with a payload of controversy about its human toll.

Not that guests find much discussion of such matters at this $3.5 million museum, devoted to the assertion that the Nevada Test Site was essential in the triumph over Eastern Bloc communist aggression. At the test site, just 65 miles northwest of Las Vegas, 100 above-ground nuclear bombs were set off from 1951 to 1963. Another 828 underground tests took place there through 1992 when a worldwide moratorium on nuclear weapons testing began.

Some say the museum - founded and largely funded by former test site workers and housed in a space leased by the Department of Energy's National Nuclear Security Administration - pushes an agenda that largely ignores the damaging and lasting effects of nuclear fallout. While others contend that the museum plays an important role in educating the public by assembling remnants of an era long shrouded in mystery.

An exhibit placard reads: "After buying U.S. secrets from traitors, the Soviets quickly developed the atom bomb in 1949 and the hydrogen bomb in 1953, and their confidence of eventual victory over the West soared. The goal was to impose totalitarian communism worldwide. Maintaining a nuclear deterrent was crucial to preventing the Cold War from becoming a hot war."

Continued cold-war fallout

Such commentaries leave some experts a bit chilled.

"I guess Vietnam and Korea weren't hot enough for them," says historian Christopher Preble, director of Foreign Policy Studies at the Cato Institute in Washington. "I actually believe the Test Site was a deterrent to World War III. I would have not been one of the nuclear protesters, but I concede there were costs. I would hope a museum would have a more balanced approach and be honest about the long-term effects, while at the same time giving credit to the people who were there."

Others are less charitable. Lymphoma survivor Preston Truman's earliest memory was of sitting on his father's knee watching a nuclear test in the 1950s from more than 100 miles away in southern Utah. Now he's the director of a nonprofit group called Downwinders made up of hundreds of people who lived in the region at the time of the tests who say their cancers were caused by radioactive residue.

"The number of civilians who were [affected] in all testing nations and the fact that we still have it hanging over our heads should be taken into account," says Mr. Truman, who now lives in Malad, Idaho.

Johnson and curator Loretta Helling insist the museum, with its Smithsonian affiliation, is a serious effort to portray that history. A rotating exhibit space and lecture series will provide opportunities for those who feel left out to be represented, Ms. Helling said.

Atomic displays

As it stands now, the displays feature a wide range of artifacts of the era including models of bombs, a case full of various Geiger counters, and films that discuss the science behind nuclear fission and radiation.

The simulation in the Ground Zero Theater is an attention-grabber that "doesn't even do justice to what it was really like, but it gives a little bit of a feel and it's in the concept of 'You're in Las Vegas,' " says Johnson, who aims for 100,000 visitors a year in a city that greeted 38 million tourists in 2004. "It's like one of those motion rides they have at the hotels."

Other displays include a litany of knickknacks from atomic-themed candy and 1950s comic books to postcards with photos of Las Vegas resorts that have mushroom clouds billowing in the distance. The gift shop sells collectibles such as Albert Einstein action figures.

Some find the lighthearted approach offensive. "Can you imagine them making a joy ride out of the collapse of the Twin Towers?" asks Truman.

State Senate minority leader Dina Titus shrugged off that aspect, noting that her own opposition to nuclear testing "doesn't mean the museum needs to be boring." Ms. Titus is on the museum's board and says she'll ensure that the institution represents more facets of the history as time goes on.

"I think the museum is very important because the story needs to be told so we don't make the mistake again," Titus says. "I wanted the museum to be more than a glorification of the bomb. It needs to tell all aspects of the story."